45 research outputs found
Ixodes ricinus is not an epidemiologically relevant vector of Bartonella species in the wood mouse (Apodemus sylvaticus)
Bartonella are hemoparasites exploiting a range of mammals as reservoir hosts. Several species are zoonotic
pathogens. Fleas, lice, and other arthropods, such as ticks, have been implicated as vectors. While the competence
of ticks as vectors of Bartonella species has recently been demonstrated, the epidemiological significance of
ticks as vectors of Bartonella species in wildlife populations remains unknown. We used the presence of deer at
study sites to control the presence of Ixodes ricinus ticks, and used this system to determine whether I. ricinus
contributes to the epidemiology of Bartonella species infections in small mammals. Ticks were present at all sites
with deer, but were absent from all sites without deer; however, the abundance of ticks on small mammals did
not affect the probability of wood mice being infected with Bartonella species. Data presented here indicate that
I. ricinus is not involved in the transmission of Bartonella in woodland rodents.A. Harrison was supported by a Ph.D. studentship from the
Department of Agriculture and Rural Development (DARD).http://www.liebertpub.com/publication.aspx?pub_id=67ab201
Invader removal triggers competitive release in a threatened avian predator
Changes in the distribution and abundance of invasive species can have far-reaching ecological consequences. Programs to control invaders are common but gauging the effectiveness of such programs using carefully controlled, large-scale field experiments is rare, especially at higher trophic levels. Experimental manipulations coupled with long-term demographic monitoring can reveal the mechanistic underpinnings of interspecific competition among apex predators and suggest mitigation options for invasive species. We used a large-scale before-after control-impact removal experiment to investigate the effects of an invasive competitor, the barred owl (Strix varia), on the population dynamics of an iconic old-forest native species, the northern spotted owl (Strix occidentalis caurina). Removal of barred owls had a strong, positive effect on survival of sympatric spotted owls and a weaker but positive effect on spotted owl dispersal and recruitment. After removals, the estimated mean annual rate of population change for spotted owls stabilized in areas with removals (0.2% decline per year), but continued to decline sharply in areas without removals (12.1% decline per year). The results demonstrated that the most substantial changes in population dynamics of northern spotted owls over the past two decades were associated with the invasion, population expansion, and subsequent removal of barred owls. Our study provides experimental evidence of the demographic consequences of competitive release, where a threatened avian predator was freed from restrictions imposed on its population dynamics with the removal of a competitively dominant invasive species
Computational Ecosystems in Evolutionary Art, and Their Potential for the Future of Virtual Worlds
Analysis of Endoscopic Radiofrequency Ablation of Biliary Malignant Strictures in Pancreatic Cancer Suggests Potential Survival Benefit
The GEOTRACES Intermediate Data Product 2014
The GEOTRACES Intermediate Data Product 2014 (IDP2014) is the first publicly available data product of the international GEOTRACES programme, and contains data measured and quality controlled before the end of 2013. It consists of two parts: (1) a compilation of digital data for more than 200 trace elements and isotopes (TEIs) as well as classical hydrographic parameters, and (2) the eGEOTRACES Electronic Atlas providing a strongly inter-linked on-line atlas including more than 300 section plots and 90 animated 3D scenes. The IDP2014 covers the Atlantic, Arctic, and Indian oceans, exhibiting highest data density in the Atlantic. The TEI data in the IDP2014 are quality controlled by careful assessment of intercalibration results and multi-laboratory data comparisons at cross-over stations. The digital data are provided in several formats, including ASCII spreadsheet, Excel spreadsheet, netCDF, and Ocean Data View collection. In addition to the actual data values the IDP2014 also contains data quality flags and 1-? data error values where available. Quality flags and error values are useful for data filtering. Metadata about data originators, analytical methods and original publications related to the data are linked to the data in an easily accessible way. The eGEOTRACES Electronic Atlas is the visual representation of the IDP2014 data providing section plots and a new kind of animated 3D scenes. The basin-wide 3D scenes allow for viewing of data from many cruises at the same time, thereby providing quick overviews of large-scale tracer distributions. In addition, the 3D scenes provide geographical and bathymetric context that is crucial for the interpretation and assessment of observed tracer plumes, as well as for making inferences about controlling processes